Process for burning brick



F. B. LAMBERT.

PROCESS FOR BURNING BRICK. APPLICATION man MAR. s. 1912.

a sHEETs-HEET I.

AVAVAZ! a;

Patented Aug. 5, 1919.

F. B. LAMBERT.

PROCESS FOR BURNING BRICK.

APPLICATION FILED MAR. 5. 1912.

3 SHEETSSHEET 2.

Patented Aug.

.Zhue/rfan' F. B. LAMBERT.

PROCESS FOR BURNING BRICK.

APPLICATION FILED MAR. 5. l9l2. v

m ,J JMM WM e P w .v Fm W W fi m 1% 9 1 L Z2 UNITED STATES PATENTOFFICE.

FRANK B. LAMBERT, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,TO

PROCESS FOR BURNING BRICK.

Specification of Letters Patent.

Patented Aug. 5, 1919.

Application filed March 5, 1912. Serial No 681,720.

- ful Improvements in Processes for Burning Brick, of which thefollowing is a specification.

The principal object of my invention is to provide a new and improvedmethod for burning bricks in kilns. Another object of my invention is toprovide a method ofv burning bricks with an economical use of fuel. Afurther object of my invention is to provide a method of burning bricksthat shall cause the heat to be advantageously distributed in the kiln.

The fundamental and important conception of my invention is the doubleuse of the heat. Heretofore when it was desired to burn a kiln of brick,it was considered necessary to supply enough heat to bring the wholekiln to the vitrifying temperature at one time. According to myinvention only enough heat is supplied from the burning fuel to heat onepart, for instance the bottom, of the kiln, and this heat is employed ina dual capacity. After it has brought the bottom of the kiln to theright temperature it is driven from the bottom to the top to raise thetemperature of the rest of the stackto the proper point successively-According to my method of procedure I heat the lower part of the kiln byforcing oi] flames thereinto and-after suflicient heat has been storedin the bottom of the kiln and after the lower courses have come to theright temperature, firing of further fuel is discontinued; To this end Iturn off the oil burners completely and supply and burn no more fuel,but use only the heat which has been put into the kiln thus far tofinish the entire kiln.

The matter of shutting off the supplying and burning of fuel is,however, incidental only to the main feature of my invention, which is adouble use of the heat. It may be observed that certain conditions arere quired in order to make it possible to carry out my invention. Thesewill appear more fully from the detailed description follow,-

v ing. It may also beobserved that complete and absolute shutting off ofthe burning of the fuel is not a strict requirement of my invention asthe addition of a small amount of heat after the main body of heat issupplied and is being driven into the top of the kiln is a matter of noconsequence. .Such slight addition of heat might be useful in temperingthe incoming air and the like,'but would be of no consequenceconsidering the process as a whole.

For the purpose of illustrating and exlaining the nature of myinvention, I shall in the following specification describe in somedetail one particular seriesof operations and the apparatus used inconnection therewith, all of which exemplify the invention. This willmake the foregoing stated objects more apparent and other objects willalso .become apparent from the following specification and claims, takenwith the accompanying drawings.

Referring to the drawings Figure 1 is a general perspective viewpartlybroken away showing a kiln in readi ness to be burned.

Fig. 2 is a transverse section of the same.

Fig. 3 is a plan view of one of the burner nozzles.

Fig. 4 is a longitudinal section of the same.

Fig. 5 is a fragmentary vertical "section through one of the arches ofthe kiln.

Fig. 6 is a vertical section taken at a right angle to Fig. 5.

Fig. 7 is an elevation of a blower tube.

Fig. 8 is a perspective view of the end thereof.

Fig. 9 is a top plan view of a portion of the blower tube.

Fig. 10 is a vertical section of the same.

The kiln shown in the drawings is a socalled temporary clamp kiln. It isconstructed under a shed roof 15 supported at its eaves by posts 16 and17 braced together so as to resist lateral thrusts as well as to sustainthe weight of the roof. The boards of the roof 15 are removable so as tofacilitate the escape of the gases and vapors from the kiln as desired.Tie rods 18 are provided for the roof 15, and the posts 17 support rails19, which constitute a crane track. The shed has extension roofs 20 atthe sides and under thesethe side walls comprise removable panels 21 ofwooden boards. A permanent steam pipe 22 with steam at about one hundredpounds pressure is car. ried above the ground along one side of the'cool, and then the burned bricks constituting.

' the kilns are taken down and hauled away.

Under one long shed 15 there may be several of these temporary clampkilns at different stages of construction and burning.

One kiln may be under theprocess of burning while another is being builtup and still another is being torn down and hauled away. In biiildingone of these kilns a la er of previously burned bricks 24' is laid at onthe ground. Then the dried bricks are piled above. These dried bricksare handled by cranes which run on the tracks 19. The bricks come fromthe driers on cars piled eight brick widths deep, and the cranes pick upa cart-load at a time and place it in the proper position for buildingup the kiln- The first installments of bricks 25 are spaced apart so asto leave transverse channels or spaces between them. Then men workingwith their hands draw the.toplay ers of bricks over to form jets 27 andthus form the arches 26.v After the arches are formed the spaces behindthe jets are filled in with extra brick placed by hand and thenadditional dried; unburned bricks 25" are piled on top by the crane. Thebricks 25 and 25, are all built up in. the kiln so that they stand onedge crisscross with narrow spaces between them. On the sides of thekiln above the arches and on the ends of the kiln from the ground upthere is placed a wall 28 of double coal bricks, the thickness of thiswall being equal to the length of a single brick. These double coalbricks are made by mix'ing'anthracite coal screenings with the clay inthe proportion roughly of eighty pounds to a thousand brick. Untside ofthe double coal brick 28 a wall of previously burned brick 29 is builtup all around the sides and ends of the kiln. The thickness of this wall29 is a brick length for the lower half. but only abrick width for theupper half. The outside face of this side and end wall 29 is thenplastered over or .scoved with a daubing made of sand and black loam soas to close the cracks between the bricks! Then a layer of previbusly.burned brick 30, the platting, is laid flat wise. allover the top of thekiln as closely as the brick can conveniently be laid, but

gases and vapors between them.

the top brick 30 are not scored, and the from the kiln can escape a Incompleted form each kiln has the folv lowing dimensions: There arethirty arches .in the kiln with about forty-two thousand brick per arch.The width of the kiln at the bottom is fifty-four brick lengths and atthe top is fifty-one brick lengths. The height of the kiln isforty-eight brick widths exelusive of the bottom brick 24: and the topplatting 30. The crane places the brick in loads each eight brickwidthsdeep and then loads are. placed sixdeep in the height of the kiln.Each pillar or leg between the arches has a horizontal thickness of fourthe arches 26, but so asflto leave openings to the lower parts of thesearches. Then little extensions'31 called dog houses are built out fromthe open ends of the arches 26. Above each dog house there is left apeep hole 61 normally'iclosed by a brick bat;

The side walls'of the completed kiln are i bracedby struts 32 and bricks33 against the side posts 17, and'the end walls of the kiln are bracedby struts '35 between the" ground and the vertical bars. 34. that lieagainst the end walls ofthe'kiln.

-On top of the kiln at regular intervals,

brick-bats or piles of brickbats 36 are placed and rods 37 are-hung fromthe tie rods 18;

the lower end of the hangerfrods' 37 barely touching the brick. batsThis is so that later on the settle? can be observed. a 4

1 05 A temporary steam pipe 38,- branchin'gf;

from the overhead steam main -22jis laidall f along the sides ofthe kilnjust above: and

beside the dog houses 31.,- This steampipe's 38 is paralleled bya-temporary'oil supply pipe 39 connected to the buried; oil main 23.--

Beside eachdog house each pipeSSand-BSL- I has respective valves 40. andiii controllingi branch outlets. An oil injector nozzle 445s connectedby i the pipes 41and 43 and elbow 42 forming an L. to. the steam outlet40, and it is also connected by a flexible tubing 47' and the endpipes'ti and 48 tothe oil outlet 45. Thus it will be seen that theinjector nozzle 44: can be swung up and down about the pipe 41 as anaxis and with the pipe 43 as a radial arm. The injector nozzle 44 has acentral conical oil outlet 49 controlled by the-needle valve 50, whichis adjusted by the hand wheel 51. The steam outlet 52 is annularsurrounding theioil outlet 49. The form of this burner, nozzle may bevaried.

For the Purpose of blowiniin steam and? 130.

air at a certain pressure in t is practice of fires burn rather close tothe do my improved method, as I shall describe presently, I provide thepipes 53. Each pipe 53 consists of four sections successively decreasingin diameter. Each section has an opening 55, just before the joint 54with the next smaller section, and around each arch 26 at each endthereof, the oil being injected by the annular steam jet issuing fromthe nozzle 52. At first only a moderate supply of oil and steam isinjected and the houses. As the bricks adjacent to the en 5 of thearches get dried out and hot the fire is forced, using more steam andoil, and at the end of about six hours the flames are driven way backintothe arches so that the two flames coming in at the ends of each'arch meet or nearly meet at the middle of the arch and thus the wholearch is filled from end to end with the oil flames. The kiln is burnedin this way for about six hours more, the fire being forced to theutmost during this time. By this time all the bricks ad acent to thearches are beginning to be red hot;

thereafter the operator begins to shut off the steam and Oll supplies,tapering down for the next eight to twelve hours.

The burners are careful to force the fires at the ends of theintermediate arches and throughout the arches at the ends of the kiln.Also they burn with considerable air at first so that there isuncombined oxygen in. the gases going up through the kiln. This oxygenenters the pores of the double coal brick 28 and burns the coal therein,thus affording a local supply of heat around the walls of the kiln. Themore intense burning at the ends of the intermediate arches andthroughout the end arches and the combustion of the anthracite coal inthe outside wall of double coal brick, all insure proper burning of thedried brick adjacent to the side and end walls of the kiln. The idealstate which the burners try to attain, say afterthey have been burningfrom ten to twenty hours, is to have an isothermal surface or zoneextending horizontally across the body of the kiln just above thearches, but rising a little all around its This has been indicated diaramedges.

otted matically on Fig. 1 by means of the line 59'.

At the end of from twenty to twenty-four the ent of the hanger rods 37.This settle may be only a fraction of an inch, but it probably indicatesthat the bricks above the arches have become so softened by the heatthat they are crushin together slightly by reason of the load of filebricks above them. Wherever the operators notice. this settle, theypromptly shut off the flames in the arch or arches directly beneath thesettling point or points and swing the corresponding nozzles 44 up abovethe dog houses 31. Then they shove the tubes 53 into the arches at whichthe flames have been shut off, puttin the small end 57 of each tube orpipe 53 in first and in such position that all the flaring nozzles 56and 57 are directed upwardly, also so that the bracket or frame 58 liesdirectly below the nozzle 44. Then the nozzle 44 1S swung down so thatit rests on the frame 58 and the steam valve 40 is opened. The steamblast going from the nozzle 44 axially into the pipe 53 has an ejectoraction and draws inwith it a large amount of air through the large openend of the pipe 53 around the nozzle 44. This mixed air and steam issuefrom the pipe 53 through the flaring-nozzles 56 and 57 and then ascendup through the bri'k-work 25 and 25'.

This blowing of steam and air is continued for about twenty-four hoursafter the fires are shut off. Very soon after the blowing of steam andair commences the mcandescence disappears. when looking into the archesthrough the .peep holes. force with which the steam is blown isregulated by the operators in accordance with the settle. The moretendency the kiln shows in any place to settle the harder the The steamand air are blown in all the arches under that place.

At the end of about twenty-four hours'of blowin that is, aboutforty-eight hours after t e fires were started, the blowing is stoppedand the dog houses are knocked down so as to give a good opportunity forair to go into the arches by natural draft. After about twenty-fourhours more. that is, about seventy-two hours after burning is started,the zone of incandescence in the kiln gets up to the top so that the redhot brick can be seen through the cracks between the brick 30 on top ofthe kiln. This marks the completion of the burning and it only remainsfor the kiln to cool down by its natural draft so that it can be takendown and the bricks hauled away. I employ the term vitrification todesignate the burning of bricks, or similar clay product, to such 'acondition that they are finished products.

in a certain type of clay product, but to conception is the double useof heat in this cover the broad idea of burning to the finish requiredfor the particular product.

While the bricks piled in the kiln are largely freed from their moistureby the preliminary drying, it is true that they have a considerablequantity of moisture in them which is driven oif by the burningespecially in the earlier stages. Soon after the fire is started a densecloud of water smoke comes off from the top of the kiln escaping throughthe openings in the top layer of brick 30. At the time the fire is shutoff this water smoke is still issuing from the kiln in some instancesand continues to do so for a considerable time thereafter. But about thetime the blowing is stopped, that is, at the end of the secondtwenty-four hours, the quantity of water smoke becomes less and when thezone of incandescence reaches the top of the kiln is has ceasedentirely.

lVhile I have practised the method defined in the appended claims invarious ways, and

with various clays, and at various places, I.

have given a specific description of only one particular series ofoperations v according thereto. This description is for kilns built andburnt by me at yard No. 22 of the Illi nois Brick Company just west ofBlue Island I The clay of'which these bricks are made is so-calledhardpan, a stratum about twenty or twenty-five feet thick overlaid byblue clay and underlaid by boulders and gravel. The overlying blue clayat this yard has all been taken oil and burned, in past years. In

- burning the hard-pan I have found that my method is advantageous forthe reason that the bricks made from the hard-pan had a tendency toclinker if burned by previously .known methods, but they do not clinkerwhen burned in accordance with my system. But my method of burning hasother advantages, among which is the shortness of time required for thecomplete operation of burning, and the saving of fuel. I have burnedmany thousand brick by my method with a consumption of only eightgallons of oil per thousand of brick, whereas I know that it is notuncommon by other methods to consume as much as. twenty to twenty-fivegal-' lons of oil er thousand of brick.

In th f0 lowing claims I employ the term elastic fluid to comprehendgases or vapors, or mixtures thereof.

In many instances it may be desirable to vary the rate and quality ofburning and the times stated above for the various steps in my processmerely illustrate one method of carrying out the latter, and I do notwish to be restricted to the exact method and application of the samebeyond the scope oil-the appended claims.

As I have-above indicated, the important particular connection. Thespecific method of procedure which I prefer to follow-requires absolutediscontinuing of the supply and burning of fuel This is because the oilburners are used as injectors, and in order to get the injector pipeinto place it is necessary to shut oil the oil burners. Such completeshutting off of the fuel is in all cases desirable from the standpointof saving fuel and of practising the process. Burning of further fuelthereafter'would, so far as carrying out the process is concerned, bemerely a waste of heat, but I wish it clearly understood that all of theadvantages of my invention may be gained without complete and absolutediscontinuance of the fire so long as the double useof the heat isgained. A small fire might be permitted to burn after the period ofblowing the body ofheat has begun, but such small fire would be merelyan evasion of the term .discontinuing." I

intend, therefore, to cover broadly the double use of the heat evenwhere absolute and complete cessation of burning is avoided by.

adding a small amount of heat.

I claim: a a

1. A process for burning clay products consisting in first arranging thesame in a kiln, next applying heat to said kiln and the products for atime sufiicient to create a heating zone of the-required temperature,then discontinuing the application of such heat and next applyinggaseous fluid to said kiln and permitting said heating zone to traversea portion thereof. 1

2. A process for burning clay products consisting in first arranging thesame-in a kiln, next applying heat to sa'idkilnand "products for a timesuflicient to create a" heating zone of the required temperature, thendiscontinuing the application of such heat, next applying gaseous fluidto said kiln and permitting sald heating zone to traverse" a portion ofsaidkiln, and then discontinuing such supply of gaseous fluid andpermitting said zone' to travel the balance of said kiln.

A process for burning clay products consisting of first arranging thesame in a kiln with a heating chamber therein, next in supplying andburning fuelin said chamber under pressure until a heating zone of therequired temperature is established through- Ollhstlld clay productsadjacent said chamber, then discontinuing such fuel supply,

'- and next supplying heated air under pressure in said chamber untilsaid zone has traveled through a portion of said kiln.

5. A process for burning clay products, consisting in first arrangingthe same in a kiln with a heating chamber therein, next in supplying andburning fuel in said chamber under pressure until a heating zone of therequired temperature is established throughout said clay productsadjacent said chamber, then discontinuing such fuel supply and burning,and next supplying air and steamunder pressure in said chamber untilsaid zone has traveled through a portion of said iln.

6. A process for burning bricks which consists in piling them into akiln, then firing a part of them for a time with carbonaceous fuel, thenshutting off said fuel and thereafter blowing elastic fluid into saidkiln to burn the remainder of the bricks.

7. A process for burning bricks which.

consists in piling them into a kiln, then firing only a part of them fora time with carbonaceous fuehand then shutting off said fuel andthereafter blowing elastic fluid into said kiln, said elastic fluidbeing introduced adjacent the points of previous firing.

8. A process of burning bricks which consists of piling them into akiln, then firing them for a time with carbonaceous fuel until theyreach the vitrifying temperature in a portion'of said kiln only, andthen blowing an excess-of elastic fluid into said kiln and discontinuingfiring with said fuel before all the bricks have reached the vitrifyingtemperature.

9. The process of burning bricks which consists of piling them into akiln, then firing them for a time with carbonaceous fuel until theyreach the desired vitrifying temperature in'the part of the kilnadjacent to the fire, then discontinuing firing with fuel and thenblowing elastic fluid into said kiln while the zone of vitrifyingtemperature travels to other parts of said kiln.

10. The process of burning bricks which consists in forming them into akiln with arches adjacent the bottom thereof and extending therethrough,then burning fuel in said arches adjacent each end thereof until a zoneof vitrifying temperature is established only in the stratum adjacentthe said arches,

troducin a burning fuel under pressure in v said arches until a zone ofvitrifying temperature is established only in the stratum adjacent saidkiln, then discontinuing such fuel burning, and supplying gaseous fluidunder pressure to said arches.

12. The process for burning bricks which consists in setting the bricksin a kiln, then firing the kiln with fuel to bring a part only of thebricks t0 the temperature of vitrification, then blowing elastic fluidin excess of the amount required for firing into the kiln until all thebricks are burned and discontinuing firing before all of the bricks arebrought to the temperature of vitrification.

13. The process for burning bricks which consists in setting the same ina kiln, then firing the kiln with fuel to heat a part only of saidbricks to the temperature required for burning, then discontinuing thefiring with fuel and blowing elastic fluid into said kiln until all thebricks have reached the temperature required for burning.

14. The process for burning bricks which consists in setting the same ina kiln, then firing the kiln with fuel to heat a part only of saidbricks to the temperature of vitrification, then discontinuing theheating effect of firing with fuel and blowing air in excess of theamount required for burning into said kiln till all the bricks havereached kiln until all the bricks have reached the temperature ofvitrification. v

16. The process of burning bricks which consists in setting the bricksin a kiln, then heating a stratum of said bricks to drive out themoisture and to bring said stratum to the'temperature of vitrification,then shutting off the fuel supply and forcing elastic fluid underpressure through said "stratum and into the adjacent stratum of unburnedbricks, thereby causing the heat of said stratum to be carried to theunburned bricks.

17. The process of burning bricks'which consists in settin the greenbricks into a kiln having an internal heating. chamber therein, thenburning fuel under forced draft to drive oil the moisture from the greenbricks and to bring to the temperature of vitrification, a stratum ofsaid bricks adjacent said heating chamber, then cuttin off the fuel andcontinuing the forced dra t to drive the heat from said heated stratumto the adgacent strata of unburned bricks driving 0 the moisture andbringin to the temperature of vitrification the u h bricks inprogression. I

18. The process of burning brickswhich consists in setting the bricks ina kiln with an internal furnace, then burning fuel under urned jacentthe furnace, and directing the fire in' forced draft, said burning beingconducted to drive off the moisture and to bring to the temperature ofvitrification a stratum only of bricks adjacent said furnace, thendiscontinuing the fuel supply and continuing to force the pressure draftto cause the heat to travel to an adjacent stratum of unburned bricksand to bring the same to the desired temperature. j

19. The process of burning brick which consists in setting the bricks ina kiln having an internal furnace, then firing said furnace with fuelunder a forced draft sufficient to cause the water smoke and othervapors to move from the stratum adsaid furnace to extend the heating ina'su'bstantially isothermal zone across the kiln to heat the bricks insaid zone, to thetemperature of vitrification, then discontinuing thefiring and continuing the forced draft to drive the water smoke forwardfrom adjacent strata, and. causing said heated-zone to travelsuccessively to said strata to bring to the temperature of vitrificationthe adjacent unburned brick in said kiln.

20. The-process of burning. bricks which consists in setting the bricksin a kiln having an internal furnace, then heating the furnace with fuelburned under a forced draft, said draft being great enough to force thewater smoke from the lower stratumof bricks adjacent the furnace throughthe remaining bricks, said firing being continued until said entirestratum is brought to the temperature of vitrification, thendiscontinuing the firing and continuing the forced draft sufficient todrive the heat from said stratumginto successive adjacent strata continuously until said desired temperature shall havebeen attained by saidadjacent strata.

21. The process of burning bricks which consists in setting said bricksin a kiln with a furnace therein, then firing said furnace under aforced draft until a highly-heated substantially isothermal Zone isattained adj acent said furnace, the bricks adjacent said zone beingstill at the temperature at which theygive off water smoke, thendiscontinuin firing and maintaining the forced draft y discharging jetsof steam in said furnace to entrain large volumes of air, thereby causinsaid highly-heated zone to travel to the adjacent bricks.

22. The process of burning bricks which consists in piling them intoakiln, then firing apart of them for a time with carbonaceous fuel tovitrify said part, then blowing elastic fluid in excess'into said kilnto vitrify the remaining bricks in the kiln, said firing beingdiscontinued prior to the-vitrification of said remainder.

23. The process of burning bricks which consists in pilingthem into akiln, then firing only a part of them for a time with carbonaceous fuelto vitrify said part, and then blowing air in excess into said fuel tovitrify the remainder of the bricks, said firing being discontinuedprior to-the vitrification of said remainder.

24. The process of burning clay products which consistsin arrangingthesame in a kiln, burningfuel to heat a stratum of said products tosubstantially the temperature of vitrification, injecting air in excessinto said kiln and discontinuing the burning of said heating fuel beforeall of said products ave attained the temperature of vitrification.

25. The process of burning clay products which consists in arranging thesame in a kiln having a heating chamber therein, burning fuel in saidheating chamber to heat a. stratum of said products to substantially thetemperature of vitrification, injecting large quantities ofelastic-fluid, into said kiln and discontinuing the burning of saidheating fuel before all'of the strata of-saidproducts have attainedthetemperature of vitrification; I

26. "The process of burning bricks or the :quired to burn said fuel, anddiscontinuing the heating effect of said firing prior to the I time whenall of said bricks have reached the temperature of vitrification. I V

27. The process of burning bricks or the like which consists in pilingsaid bricks into a kiln, then firing a part of said bricks to bring thesame substantially to the temperature of vitrification, injecting air?under pressure into said kiln in excess of the amount required for theburning of said fuel and reducing the fire and discontinuing the heatingeffect of the same beforegall of said bricks have been brought to thedesired temperature of vitrification.

28. The process of manufacturing and burning bricks, which consists inmixing carbonaceous material with the clay, their forming the clay intobricks, then piling the bricks into a kiln, then firing said bricks withan excess of air to bring a part only of said bricks .to the temperatureof vitrification and to burn out the carbonaceous material, thendiscontinuing the heating effect of firing and blowing air through saidheated bricks'to said unburned bricks in order to burn out thecarbonaceous material and to vitrify the same. 1

v 29. The process of. manufacturing and burning bricks, which consistsin mixing finely divided coal withclay then forming the: clay containingthe coal into bricks, then iling said bricks into a kiln, then firingsaid rlcks with an excess of air to bring a part only of said bricks tothe temperature of vitrification and to burn out the carbonaceousmaterial, then discontinuing the heating effect of firing and blowingair in excess through said heated bricks to said unburned bricks inorder to burn out the carbonaceous material and to vitrify all of thebricks.

30. The process of manufacturing bricks which consists in mixingcarbonaceous material with part of the clay, then forming the clay intobricks, then iling the bricks into a kiln, then firing said bricks tobring the lower strata to the temperature of vitrification and to burnthe carbonaceous material in said bricks, then discontinuing the heatingeffect of said firing and blowing excess of air through said heatedbricks to said unburned bricks in order to burn out the carbonaceousmaterial and to vitrify all of the bricks. I

31. The process of burning bricks which consists of setting the bricksinto a kiln for burning, then heating one extreme of said kiln byblowing flames under forced draft into said kiln under as great apressure as is required to force the major portion of the gases andproducts of combustion out of the opposite end of the kiln, said firebeing directed to cause the formation of a zone of incandescenceextending completely across said extremity of the kiln, thereaftershutting off the fuel and blowing gaseous fluid through said kiln in thesame general direction as the line of movement of the products ofcombustion through the kiln, to move said zone of incandescence throughthe length of the kiln to the other extremity thereof.

32. In a process for burning brick, the following steps, setting thebrick in a kiln in close relation. then applying a limited quantity ofheat from an external source to the lower part of the kiln only, tobring said lower partto the temperature required for vitrification, andalso to store a large body of heat in said lower part, then carryingsaid large body of heat as a body from the lower part to the upper partof the kiln and thereby bringing the upper part to the requiredten'iperature of vitrification by means of the stored heat in said lowerpart only.

33. In a process for burning brick, which comprises setting the brick inclose relation to each other in a stack, applying heat from an externalsource to the lower part of the stack only, to heat the bricks in saidlower plying heat from an external source to the bottom of the kiln onlyto burn the lower portion of the kiln and Store a body of internal heatin said lower portion while the upper portion is still green and wet.then burning the other portion of the kiln by the application of theinternal heat contained in the lower burned portion and finally drivinglall of the body of heat out of the top of the (iln.

The process of burning bricks, which comprises stacking the bricks in akiln, burning fuel adjacent the stack and applying the heat thereof tothe bottom of the stack only, until a large enough portion of the lowerpart of the kiln has been brought to the temperature of vitrification,to store enough heat to burn the top of the kiln, then moving the heatfrom the lower heated portion up through the upper portion to completethe burning of said upper portion with said stored heat, andsimultaneously cooling down the lower part of the stack.

In testimony whereof, I have subscribed my name.

FRANK B. LAMBERT.

